And The affix ap comes optionally after the verb yam 'to surround' when the upasarga -s sam , upa , ni and vi are in composition ; or even when it is without upasarga -less.,
This debars घञ्. As संयामः or संयमः 'restraint'; उपयामः or उपयमः 'marriage'; नियामः or नियमः 'restrictive rule'; वियामः or वियमः 'check, distress'; यामः or यमः ।,